Circuit-breaker.



PATENTED JUNE 7, 1904.

w. J. LLOYD.

CIRCUIT BREAKER. APPLICATION rum) AUG. 1a, 1903.

1Y0 MODEL.

L'NVENTOR. WilliamJLlogd.

WITNESSES A T TORNE Y1 citizen of the United States, and a resident of constructed a change in the position aifects UNITED STATES Patented June '7, 1904-,

PATENT OFFICE.

IVILLIAM J. LLOYD, OF PITTSFIELD, MASSACHUSETTS, ASSIGNOR TO STANLEY ELECTRIC MANUFACTURING COMPANY, OF PITTSEIELD, MASSACHUSETTS, A CORPORATION OF NEW JERSEY.

CIRCUIT-BREAKER.

SPECIFICATION forming part of Letters Patent No. 761,776, dated June '7, 1904.

Application filed August 19, 1903.

To all whom, it may concern:

Be it known that I, WILLIAM J. LLOYD, a

Pittsfield, Massachusetts, have invented certain new and useful Improvements in Circuit- Breakers, of which the following is a specification.

My invention relates to circuit-breakers, and is especially adapted for use in streetcar service. In practice the circuit-breakers on street-cars are placed in many different positions, as the convenience of each case dictates. With circuit-breakers as ordinarily the setting of the tripping device, thereby changing the opening-point of the breaker. By my invention I am able to provide a circuit-breaker which may be calibrated for any position and which will not have its openingpoint changed by any alteration of its position. I accomplish this by providing a balanced armature for the tripping device. The use of a balanced armature necessitates the employment of a spring for the retractive force. With the ordinary arrangement springs are not suitable for the most eflicient operation of a circuit-breaker, since the movement of the armature when it is drawn up by its solenoid elongates the spring and increases the retractive force as the armature moves. Thus the increasing magnetic attraction due to the movement of the armature is partly annulled, and the closing with a hammer blow, which is very desirable in circuit-breakers, is prevented. By my invention I so arrange the spring that the retractive force on the armature as it is drawn up is not increased, and a hammer-blow is obtained with a balanced armature.

In the accompanying drawing, A represents a switch which when closed connects thecontacts a a. Switch A is pivoted at 7), and is retracted by spring B, which tends to pull the switch open. The switch is normally held closed by the catch D, which is engaged by the pivoted armature E. F is the solenoidcoil for the circuit-breaker, connected in series with contacts a (0, adapted to draw up the Serial No. 169,993. (No model.)

outer end of armature E. Armature E is pivoted at e and is balanced with respect to the pivot. The armature is normally held in the position shown in the drawing by spring G. Spring G is arranged so that it is at all times nearly parallel to the line joining pivot e and the point of attachment of the spring to the armature. Thus the movement of armature E as it is drawn up by the solenoid in-' creases the tension of spring G only to a very small extent. Moreovelyas armature E is drawn up by its solenoid the angle between the spring and the line joining pivot a with the point of attachment of the spring decreases, so that the component of the retractive force of the spring which opposes the attraction of the solenoid is diminished. Thus the retractive force opposing the magnetic attraction of the solenoid may be made the same at open and closed positions of the armature or may be made to diminish as the armature closes. Thus the advantages of a balanced armature are obtained as regards the accuracy of the calibration for all positions of the breaker, and also the advantages of a quick and positive movement of the armature are obtained. The tension of spring G may be adjusted by means of the setting-nut 9. Thus the tripping-point of the circuit-breaker may be adjusted Without altering the relation between the position of the armature and the retract ive force exerted upon it by thespring.

It is evident that the use of my tripping device is in no way limited to the particular type ofswitch here shown, but may be used with any well-known type of switch adapted for the purpose. Accordingly I do not desire to limit myself to the particular construction and arrangement of parts here shown, since changes therein which do not depart from the spirit of my invention and which are within the scope of the appended claims will be obvious to those skilled in the art.

Having thus fully described my invention, I claim as new and desire to protect by Letters Patent 1. In a circuit-breaker, a solenoid, a balanced armature therefor, a retraetile spring for said armature so disposed that the retractive force on said armature diminishes as said armature is attracted by said solenoid, and a switch adapted to be operated by the movement of said armature.

2. In a circuit-breaker, a solenoid, a balanced armature therefor, a retractile spring for said armature so disposed that the tension of said spring is exerted in a direction nearly parallel to the line joining the pivot of said armature and the point of attachment of said spring to said armature, and a switch adapted to be operated by the movement ofsaid armature.

3. In a circuit-breaker, a solenoid, a balanced armature therefor, a retractile spring for said armature so disposed that the component of spring tension opposing the attraction 01 said solenoid on said armature diminishes as said armature is attracted by said solenoid, and a switch adapted to be operated by the movement of saidv armature.

4. In a circuit-breaker, a solenoid, a balanced armature therefor, a retractile spring for said armature so disposed that the tension of said spring is exerted in a direction nearly parallel to the line joining the pivot of said armature and the point of attachment of said spring to said armature, means for adjusting the tension of said spring without changing the direction of said tension, and a switch adapted to be operated by the movement of said armature.

5. In a circuit-breaker, a switch, a spring tending to open said switch, a catch carried by said switch, a solenoid, a pivoted armature balanced with respect to its pivot and engaging said catch and adapted to be attracted by said solenoid and means adapted to restrain said armature.

6. In a circuit-breaker, a switch, a spring tending to open said switch, a catch carried by said switch, a solenoid, a balanced armature engaging said catch and adapted to be attracted by said solenoid, and a retractilc spring for said armature so disposed that the component of spring tension opposing the attraction of said solenoid on said armature diminishes as said armature is attracted by said solenoid.

7. In a circuit-breaker, a solenoid, a balanced armature therefor, means for exerting a retractive force on said armature diminishing as said armature attracted by said solenoid, and a switch adapted to be operated by the movement of said armature.

8. In a circuit-breaker, a switch, a solenoid, an armature adapted to be attracted by said solenoid and by its movement to operate said L. A. HAWKINS, R. E. HAYNEs. 

